Question

The water level in a lake was monitored and was noted to have changed -2 1/3 inches in one year. The next year it was noted to have changed -1 5/6 inches. What was the total change in the water level over the two years?

Answer 1

Answer:

The total change in water level over the past 2 years is $\displaystyle -4 \frac{1}{6}$.

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

1. Brackets
2. Parenthesis
3. Exponents
4. Multiplication
5. Division
6. Addition
7. Subtraction

• Left to Right

Fractions

• Proper and Improper

Numbers

• Least Common Multiple (LCM)

Step-by-step explanation:

Step 1: Define

Identify

Year 1 water change:  $\displaystyle -2 \frac{1}{3}$

Year 2 water change:  $\displaystyle -1 \frac{5}{6}$

Step 2: Find Total Water Change

1. [Set up] Add yearly water changes:                                                                $\displaystyle -2 \frac{1}{3} + -1 \frac{5}{6}$
2. [Fractions] Convert to improper:                                                                     $\displaystyle \frac{-7}{3} - \frac{11}{6}$
3. [Fraction] Rewrite [LCM]:                                                                                  $\displaystyle \frac{-14}{6} - \frac{11}{6}$
4. [Order of Operations] Subtract:                                                                       $\displaystyle \frac{-25}{6}$
5. [Fraction] Convert to proper:                                                                           $\displaystyle -4 \frac{1}{6}$